Giant Pacific Octopus
Enteroctopus dofleini, also known as the Giant Pacific octopus (GPO) or North Pacific Giant octopus, is a large marine cephalopod belonging to the phylum Mollusca, and genus Enteroctopus. Its spatial distribution includes the coastal North Pacific, along California, Oregon, Washington, British Columbia, Alaska, Russia, northern Japan and Korea. It can be found from the intertidal zone down to depths of 2,000 m (6,600 ft), and is best adapted to cold, oxygen-rich water. It is arguably the largest octopus species, based on a scientific record of a 71 kg (156 lb) individual weighed live. The alternative contender is the seven-arm octopus (Haliphron atlanticus) based on a 61 kg (134 lb) carcass estimated to have a live mass of 75 kg (165 lb). However, a number of questionable size records would suggest E. dofleini is the largest of all octopus species by a considerable margin. Description All cephalopods have bilateral symmetry, a shell gland, a mantle, and well-developed head with sucker covered arms. The octopus has eight arms, each of which has two rows of suckers. Many of the suckers are lined with papillae or hooks for adhesion. The mantle of the octopus is spherical in shape and contains most of the animal's major organs. By contracting or expanding tiny pigment-containing sacs within cells known as chromatophores, an octopus can change the color of its skin, giving it the ability to blend into the environment. Sub categories of chromatophores include iridophores (reflective platelets) and leucophores (refractive platelets). Octopuses are also able to alter their skin texture, providing even better camouflage. Dermal muscles in the octopus's skin can create a heavily textured look through papillation, or cause skin to appear smooth. All of these abilities are under nervous system control. E. dofleini is distinguished from other species by its sheer size. Adults usually weigh around 15 kg (33 lb), with an arm span of up to 4.3 m (14 ft). The larger individuals have been measured at 50 kg (110 lb) and have a radial span of 6 m (20 ft) However, highly questionable records of specimens up to 272 kg (600 lb) in weight with a 9-m (30-ft) arm span have been reported. Guinness World Records lists the biggest as 136 kg (300 lb) with an arm span of 9.8 m (32 ft) American zoologist G.H. Parker found that the largest suckers on a GPO is about 6.4 cm (2.5 in) and each can support 16 kg (35 lb) each. Octopuses also have chemotaxis, or the ability to taste by touch. Distribution The bull shark is commonly found worldwide in coastal areas of warm oceans, in rivers and lakes, and occasionally salt and freshwater streams if they are deep enough. It is found to a depth of 150 metres (490 ft), but does not usually swim deeper than 30 metres (98 ft). In the Atlantic, it is found from Massachusetts to southern Brazil, and from Morocco to Angola. In the Indian Ocean, it is found from South Africa to Kenya, India, and Vietnam to Australia. Behavior Octopuses are ranked as the most intelligent invertebrates. In the third century AD, Roman natural historian Claudius Aelianus wrote "Mischief and craft are plainly seen to be the characteristics of this creature." Giant Pacific octopuses are commonly kept on display at aquariums due to their size and interesting physiology, and have demonstrated the ability to recognize humans that they frequently come in contact with. These responses include jetting water, changing body texture, and other behaviors that are consistently demonstrated to specific individuals. They have the ability to solve simple puzzles, open childproof bottles and use "tools". The octopus brain has folded lobes (a distinct characteristic of complexity), visual and tactile memory centers. They have about 300 million neurons.They have been known to open tank valves, disassemble expensive equipment and generally wreak havoc in labs and aquariums. Some researchers even claim that they are capable of motor play and having personalities. Some claim that octopuses are psychic, as Paul was made famous by predicting all seven winning teams in the 2010 FIFA World Cup, although this is not scientifically supported. Preferred Objects *Shelter: Underwater Cave *Enrichment: Rattle Ball, Treasure Chest *Animal Food: Fish, Krill, Shrimp Category:Invertebrates Category:Zoo Palace Category:Toshiko Games Category:ZP Animals Category:Aquatic Animals